Parallel-disposed integral heat exchanger

ABSTRACT

In a parallel integrated heat exchanger achieved by joining a plurality of heat exchangers with their heat exchanging units facing opposite each other and integrated fins formed to be shared by adjacent heat exchangers, performance-improving louvers  31   a  and  32   a  are formed between the tubes of the individual heat exchangers and heat transfer prevention louvers  32   b  are formed over the entire area between the tubes  3  of a condenser  5  and the tubes  7  of a radiator  9.  The heat transfer prevention louvers  32   b  are formed continuous to, at least, the performance-improving louvers  32   a  formed at one of the heat exchangers. The heat transfer prevention louvers  32   b  and the performance-improving louvers  32   a  formed continuously are made to incline along the same direction. By forming the heat transfer prevention louvers over the area of fins located between the tubes of one of the adjacent heat exchangers and the tubes of the other heat exchanger in a specific manner, the manufacturing process is facilitated.

TECHNICAL FIELD

The present invention relates to a parallel integrated heat exchangerhaving a plurality of heat exchangers provided next to one another alongthe direction of air flow, in which the heat exchanging units ofadjacent heat exchangers are linked together facing opposite each other.More specifically, it relates to a parallel integrated heat exchanger inwhich fins of adjacent heat exchangers are integrated.

BACKGROUND ART

The restrictions imposed with regard to available installation space invehicles in recent years have necessitated a plurality of heatexchangers (e.g., a condenser and a radiator) fulfilling differentfunctions to be integrated. Examples of such integrated heat exchangersinclude the structure disclosed in Japanese Unexamined Utility ModelPublication No. H 2-14582.

In this integrated heat exchanger, a first heat exchanger and a secondheat exchanger are provided in parallel and the fins of these heatexchangers are integrated to reduce the air flow resistance and thenumber of assembly steps. In addition, heat transfer prevention louversare formed in the areas of the integrated fins located between the tubesof the first heat exchanger and the tubes of the second heat exchangerto lessen the degree to which heat exchangers affect the temperature ofother heat exchangers.

The publication also discloses that the heat transfer prevention louversformed at the fins are formed in a shape roughly identical to that ofnormal louvers located between the tubes of the heat exchangers and thatthe heat transfer prevention louvers are constituted of symmetricallouver groups, each having louvers distanced from the louvers of othergroups, formed between a tube of the first heat exchanger and thecorresponding tube in the second heat exchanger (see FIG. 1 of thepublication).

However, it becomes difficult to manufacture the parallel integratedheat exchanger described above adopting a structure in which the heattransfer prevention louvers are symmetrically formed over a distancebetween the tubes of one of the plurality of heat exchangers adjacent toeach other and the tubes of the heat exchangers if the heat exchangersinstalled in parallel need to be set closer to each other. In addition,it is not designed by taking into consideration how heat transferprevention louvers, which will effectively prevent heat transfer, may bemanufactured or how the process of manufacturing the louvers themselvesis to be facilitated and, therefore, it cannot easily be put intopractical use.

Accordingly, an object of the present invention is to provide a parallelintegrated heat exchanger having a plurality of heat exchangers set inparallel and fins of adjacent heat exchangers integrated, whichfacilitates the production of heat transfer prevention louvers byforming the heat prevention transfer louvers in a particular manner andalso achieves a full heat transfer prevention effect regardless of thedistance between the parallel-set heat exchangers.

DISCLOSURE OF THE INVENTION

The parallel integrated heat exchanger according to the presentinvention, having a plurality of heat exchangers each having a heatexchanging unit constituted of fins and a plurality of tubes laminatedvia the fins and tanks provided along the direction in which theplurality of tubes are laminated, to communicate with the individualtubes, with adjacent heat exchangers joined with their heat exchangingunits facing opposite each other and their fins formed as integratedcommon members, is characterized in that performance-improving louversformed between the tubes of each of the heat exchangers and heattransfer prevention louvers formed over the entire area between thetubes of one of the adjacent heat exchangers and the tubes of the otherheat exchanger are provided at the fins and that the heat transferprevention louvers are formed continuously to, at least,performance-improving louvers formed at one of the heat exchangers.

The performance-improving louvers, which are formed in the areas betweenthe tubes of the individual heat exchangers to promote the exchange ofheat through enhanced exposure to the passing air, may be constituted asa single group or a plurality of groups of continuous louvers. Inaddition, the heat transfer prevention louvers, which are formed overthe entire area between the tubes of one of the adjacent heat exchangersand the tubes of the other heat exchanger, are provided to reduce thedegree of heat transfer that occurs from the heat exchanger on one sideto the heat exchanger on the other side via the fins. Theperformance-improving louvers and the heat transfer prevention louversmay be constituted as inclining louvers that incline relative to thesurfaces of the fins or as parallel louvers that lie parallel to thesurfaces of the fins.

In addition, it is desirable to form the individual louvers formedcontinuously to one another in a uniform mode. Achieving a uniformformation mode means that when the fins are viewed from the side onwhich the louvers are formed, the heat transfer prevention louvers areformed in a pattern identical to the pattern of theperformance-improving louvers, and when the heat transfer preventionlouvers incline relative to the surfaces of the fins, for instance, thedirection along which the heat transfer prevention louvers open and thedirection along which the performance-improving louvers open must match(they must incline in a uniform direction). If the heat transferprevention louvers are to be formed so that they project out parallel tothe surfaces of the fins, on the other hand, the heat transferprevention louvers must be made to project out continuously in a patternidentical to the pattern in which the performance-improving louvers areformed.

By assuming the structure described above, the exchange of heat betweenthe air passing between the fins and the fluid flowing inside the tubesis promoted by the performance-improving louvers in the individual heatexchangers provided in parallel and the heat transfer prevention louversprevent the adjacent heat exchangers from thermally affecting each otherreadily. In particular, since the heat transfer prevention louvers areformed over the entire area between the tubes of one of the adjacentheat exchangers and the tubes of the other heat exchanger, heat transfercan be inhibited with a high degree of reliability even when thedistance between the adjacent heat exchangers is reduced. In addition,since the heat transfer prevention louvers are formed continuously to,at least, the performance-improving louvers formed at one of the heatexchangers and the individual louvers formed continuously adopt auniform formation mode, it is not necessary to employ special processeswhen manufacturing the heat transfer prevention louvers.

In correspondence to the tube widths at the individual heat exchangers,the heat transfer prevention louvers adopting one of the followingstructures may be formed. First, if the tube widths of the adjacent heatexchangers are different, an even number of louver groups achieved byaligning roughly equal numbers of louvers along the direction in whichthe heat exchangers are provided in parallel (i.e., the direction of thewidth of the fins and the direction of the air flow) may be evenlyformed in series at each fin. In other words, two or four louver groupsmay be serially formed along the direction of air flow.

In this structure, since the adjacent heat exchangers have differenttube widths, the areas between the tubes at one of the heat exchangersand the tubes at the other heat exchanger are offset from the center ofthe width of the fins. In addition, since an even number of louvergroups are evenly formed at each fin along the width of the fins, nolouvers are formed at the centers of the fins along their width. As aresult, louvers can be formed at areas corresponding to the areas of thefins located between the tubes at one heat exchanger and the tubes atthe other heat exchanger.

Next, if the tube widths of the adjacent heat exchangers are roughlyequal to each other, an odd number of louver groups achieved by aligningroughly equal numbers of louvers along the direction in which the heatexchangers are provided in parallel may be evenly formed in series ateach fin. For instance, three louver groups may be serially formed alongthe direction of air flow.

In this structure, the areas between the tubes at one of the adjacentheat exchangers and the tubes at the other heat exchanger are each setat an approximate center along the width of the fins, and since an oddnumber of louver groups are evenly formed at the fins along thedirection of their width, louvers are formed at the centers along thewidth of the fins. Thus, the areas at which the louvers are formed canbe made to correspond to the areas of the fins located between the tubesat one heat exchanger and the tubes at the other heat exchanger.

Furthermore, the area between adjacent louver groups formed at a fin maybe formed as a flat surface continuous with the surface of the fin, oras a non-flat surface by reducing the distance between the louvergroups. A non-flat structure may be achieved by, for instance, forming alink portion with its peak shape between louver groups.

When the area between adjacent louver groups is formed as a flatportion, a smooth flow of air guided by the louvers to pass between thefins is achieved in an effective manner, whereas when the area betweenadjacent louver groups is formed as a smaller non-flat portion, animprovement in heat exchanging performance is achieved, since the ratioof the area on the fin surface occupied by the louvers is increased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a) and 1(b) illustrate the overall structure of the parallelintegrated heat exchanger according to the present invention, with FIG.1(a) presenting its front view and FIG. 1(b) presenting its plan view;

FIG. 2 is a perspective if the parallel integrated heat exchanger inFIGS. 1(a) and 1(b);

FIG. 3 is an enlarged perspective of the tubes of the individual heatexchangers and the fins in the parallel integrated heat exchangeraccording to the present invention;

FIG. 4 shows the positional relationship between the tubes at theindividual heat exchangers and the louvers at the fins in the parallelintegrated heat exchanger according to the present invention, achievedwhen the tube width at the condenser is larger than the tube width atthe radiator and two louver groups are evenly formed at the fins. Theupper section of FIG. 4 is a sectional view of a portion obtained bycutting the fins and the tubes along the direction of the width of thefins, and the lower section of FIG. 4 illustrates the configuration oflouvers at the fins;

FIG. 5 presents a characteristics diagram showing the condenser heatexchanging performance measured in the parallel integrated heatexchanger according to the present invention provided with the heattransfer prevention louvers and in a heat exchanger without any heattransfer prevention louvers;

FIG. 6 shows the positional relationship between the tubes at theindividual heat exchangers and of the louvers at the fins in theparallel integrated heat exchanger according to the present invention,achieved when the tube width at the radiator is larger than the tubewidth at the condenser and four louver groups are evenly formed at eachfin. The upper section of FIG. 6 is a sectional view of a portionobtained by cutting the fins and the corresponding tubes along thedirection of the width of the fins, and the lower section of FIG. 6illustrates the configuration of louvers at the fins;

FIG. 7 shows the positional relationship between the tubes at theindividual heat exchangers and the louvers at the fins in the parallelintegrated heat exchanger according to the present invention, achievedwhen the tube width at the radiator is set roughly equal to the tubewidth at the condenser and three louver groups are evenly formed at eachfin. The upper section of FIG. 7 is a sectional view of a portionobtained by cutting the fins and the corresponding tubes along thedirection of the width of the fins, and the lower section of FIG. 7illustrates the configuration of louvers at the fins;

FIG. 8 shows the positional relationship between the tubes at theindividual heat exchangers and of the louvers at the fins in theparallel integrated heat exchanger according to the present invention,presenting another example in which the tube width at the radiator isset roughly equal to the tube width at the condenser and three louvergroups are evenly formed at each fin. The upper section of FIG. 8 is asectional view of a portion obtained by cutting the fins and the tubesalong the direction of the width of the fins, and the lower section ofFIG. 4 illustrates the configuration of louvers at the fins;

FIG. 9 shows the positional relationship between the tubes at theindividual heat exchangers and the louvers at the fins in the parallelintegrated heat exchanger according to the present invention, achievedwhen the tube width at the radiator is set roughly equal to the tubewidth at the condenser and two louver groups are formed with one louvergroup having a larger number of louvers than the other at each fin. Theupper section of FIG. 9 is a sectional view of a portion obtained bycutting the fins and the corresponding tubes along the direction of thewidth of the fins, and the lower section of FIG. 9 illustrates theconfiguration of louvers formed at the fins; and

FIG. 10 shows the positional relationship between the tubes at theindividual heat exchangers and the louvers at the fins in the parallelintegrated heat exchanger according to the present invention, achievedwhen the tube width at the radiator is set roughly equal to the tubewidth at the condenser and the louvers at the fins are formed asparallel louvers. The upper section of FIG. 10 is a sectional view of aportion obtained by cutting the fins and the tubes along the directionof the width of the fins, and the lower section of FIG. 10 illustratesthe configuration of louvers formed at the fins.

THE BEST MODE FOR CARRYING OUT THE INVENTION

The following is an explanation of embodiments of the present invention,given in reference to the drawings. In FIGS. 1(a) through 3, a parallelintegrate heat exchanger 1 achieved by joining a condenser 5 and aradiator 9 as one unit is constituted of an aluminum alloy. Thecondenser 5 comprises a pair of tanks 2 a and 2 b, a plurality of flattubes 3 communicating between the pair of tanks 2 a and 2 b andcorrugated fins 4 inserted and bonded between the individual tubes 3.The radiator 9 comprises a pair of tanks 6 a and 6 b formed separatelyfrom the tanks at the condenser, a plurality of flat tubes 7communicating between the pair of tanks and formed separately from thetubes 3 at the condenser and fins 4 also constituting the fins of thecondenser 5 and inserted and bonded between the individual tubes 7.

In the individual heat exchangers 5 and 9, the plurality of tubes 3 and7 and the fins 4 constitute heat exchanging units that perform heatexchange for fluid flowing inside the tubes and the air passing betweenthe fins, and the individual heat exchanging units facing opposite eachother are assembled to achieve an integrated state.

The tubes 3 of the condenser 5, which adopts a structure of the knownart achieved by partitioning the internal space with numerous ribs toimprove the strength, may be formed through extrusion molding. Inaddition, the tanks 2 a and 2 b of the condenser 5 are each formed byblocking the openings at the two ends of a cylinder member 10 with lids11, with a plurality of tube insertion holes 12 at which the tubes 3 areinserted at the circumferential wall of the cylinder member 10, andtheir internal space partitioned by partitioning walls 15 a, 15 b, and15 c to form a plurality of low passage chambers. An intake port 13through which the coolant flows in is provided at a position located atthe portion of the tank constituting the most upstream side flow passagechamber and an outlet port 14 through which the coolant flows out isprovided at a position located at the portion of the tank constitutingthe most downstream side flow passage chamber.

The structural example shown in FIGS. 1(a) and 1(b), one of the tanks,i.e., the tank 2 a, is divided into three flow passage chambers by thetwo partitioning walls 15 a and 15 b, the other tank 2 b is divided intotwo flow passage chambers by one partitioning wall 15 c, and the intakeport 13 and the outlet port 14 are provided at the tank 2 a to allow thecoolant having flowed in through the intake port 13 to travel betweenthe tanks twice before flowing out through the outlet port 14.

The tubes 7 of the radiator 9, on the other hand, are constituted ofelectro-resistance-welded tubes with no ribs partitioning the internalspace. In addition, the tanks 6 a and 6 b of the radiator 9 each assumea cylindrical shape with a rectangular cross section, constituted of afirst tank member 16 having tube insertion holes at which the tubes 7are inserted therein and achieving a U-shaped cross section and a secondtank member 17 set between the sidewalls of the first tank member 16 toconstitute a circumferential wall of the tank 6 together with the firsttank member 16, with the openings at the two ends of the cylindricalbody closed off with a blocking plates 18.

The blocking plates 18 are each constituted of a flat plate formed in arectangular shape in conformance to the cross sectional shape of thetank and having projections formed at two sides thereof facing oppositeeach other so that they are mounted at the openings of the cylindricalbody by fitting the projections at fitting holes 19 formed at the firsttank member 16 and the second tank member 17.

Retaining grooves are formed at the second tank member 17 by distendingand bending the two side edges into a U-shape, and the tank member 16and 17 are joined with each other by fitting the sidewall ends of thefirst tank member 16 at the retaining grooves. The first tank member 16and the second tank member 17 are joined with each other at a positiondistanced from the side at which the tubes 7 are connected, furtheroutward relative to the position at which the tank 6 faces opposite thetank 2 of the condenser 5.

At one of the tanks of the radiator 9, i.e., the tank 6 b, an intakeport 26 through which the fluid flows in is provided, and an outlet port27 through which the fluid flows out is provided at the other tank 6 a.In this example, the internal spaces at both tanks 6 a and 6 b are notpartitioned, so that the fluid having flowed in through the intake port26 is allowed to travel from the tank 6 b to the other tank 6 a via allthe tubes 7 before it flows out through the outlet port 27.

Further outward relative to the laminated tubes 3 and 7 (at the upperand lower ends of the heat exchanging units in FIG. 1a), side plates 20are brazed via the fins 4 and the condenser 5 and the radiator 9 arejoined as a single unit by the side plates 20. The side plates 20 mayeach be constituted of a single plate shared by the two heat exchangers,with at least one ventilation hole 21 formed at the plate surface at aposition facing opposite the area between the condenser 5 and theradiator 9.

The at least one ventilation hole 21 is formed as an elongated holeextending along the direction of the length of the side plate 20, and itcommunicates between the area between the condenser 5 and the radiator 9and the outside, thereby ensuring that heat radiation from the condenser5 is not hindered by air at a relatively high temperature stagnatingbetween the condenser 5 provided on the upstream side and the radiator 9provided on the downstream side when the heat exchanger is operating ata low air velocity and promoting heat radiation from the radiator 9 bydirectly guiding air at a relatively low temperature flowing in via theventilation hole 21 to the radiator 9.

In addition, as illustrated in FIG. 1(b), the side plates 20 are notbonded with the tanks 2 a and 2 b on the condenser side but are set awayfrom them over a specific distance, and are brazed to the tanks 6 a and6 b on the radiator side. The side plates 20 and the tanks 6 a and 6 bmay be bonded through brazing simply by placing the two ends of eachside plate 20 in contact with the surfaces of the first tank member 16or they may be brazed with the ends of the side plates 20 inserted atinsertion holes formed at the first tank member 16.

In this example, the condenser 5 and the radiator 9 are joined to forman integrated unit by the side plates 20 and the fins 4 formed to beshared by the two heat exchangers, and the tanks 2 a and 2 b of thecondenser 5 and the tanks 6 a and 6 b of the radiator 9 are assembled ina separated state.

The fins 4 are each constituted by continuously forming bent apicalportions 4 a and flat portions 4 b located between the apical portionsalong the direction of the length of the tubes, and as shown in FIG. 4,louvers 30 are formed at each of the flat portions 4 b. The louvers 30each rise at an incline relative to the surface of the flat portions 4 band project out to the front side and to the rear side, so that airpassing between the fins is guided by the louvers to pass through theflat portions 4 b.

Such louvers 30 are formed continuously to constitute a louver groupand, in this example, two louver groups, i.e., a first louver group 31and a second louver group 32 are provided in series along the directionof the width of the fin 4 (i.e., the direction along which the condenserand the radiator are provided in parallel). Each louver group isconstituted by aligning a plurality of uniformly shaped louvers whichare continuously formed and inclined along the same direction, and thefirst louver group 31 and the second louver group 32 are formedsymmetrically to each other relative to the center of the fin width. Inaddition, a flat portion 33 where no louver is present is formed betweenthe first louver group 31 and the second louver group 32.

The width of the tubes at the condenser 5 is set larger than the widthof the tubes at the radiator 9, the flat portions 33 are formed in thearea located between the tubes of the condenser 5 and louversconstituting the second louver group 32 are formed at the fins 4 in thearea located between the tubes 3 of the condenser 5 and the tubes 7 ofthe radiator 9. In other words, the second louver group 32 isconstituted by continuously forming performance-improving louvers 32 alocated between the tubes of the radiator 9 and heat transfer preventionlouvers 32 b located between the tube 3 of the condenser 5 and the tube7 of the radiator 9, with a portion of the second louver group 32utilized to constitute heat transfer prevention louvers. All the louvers30 in the first louver group 31, on the other hand, are constituted asperformance-improving louvers 31 a.

When assembling the parallel integrated heat exchanger structured asdescribed above, the first tank member 16 and the second tank member 17are assembled together and, at the same time, the blocking plates 18 aremounted by fitting them at the fitting holes 19 of the tank member 16and 17 to form the tanks 6 a and 6 b of the radiator 9. Then, the tubes3 and 7 are respectively inserted at the pair of tanks 2 a and 2 b andthe pair of tanks 6 a and 6 b of the condenser 5 and the radiator 9, thecommon fins 4 are mounted between the individual tubes and the sideplates 20 are mounted via the fins further toward the outside of thelaminated tubes 3 and 7.

The individual heat exchangers 5 and 9 thus assembled are fixed by usinga jig in a state in which their heat exchanging units are set oppositeeach other in parallel and the areas over which the tanks 2 a and 2 b ofthe condenser 5 and the tanks 6 a and 6 b of the radiator 9 are joinedwith the tubes 3 and 7 respectively are set aligned along the lateraldirection over a small distance from each other. Then, the entireassembly is brazed in a furnace to connect the condenser 5 and theradiator 9 as a unit via the side plates 20 and the fins 4.

The integrated heat exchanger thus achieved is mounted with thecondenser 5 set on the upwind side. A high-temperature, high-pressurecoolant flows into the condenser 5 from the compressor (not shown), andthis coolant undergoes heat exchange with the air passing through thefins 4 while it travels through the tubes 3. In addition, the enginecooling water flows into the radiator 9, and the cooling water undergoesheat exchange with the air passing through the fins 4 while it travelsthrough the tubes 7.

Since the performance-improving louvers 31 a and 32 a are formed at thefins 4 between the tubes of the individual heat exchangers, the fluidflowing through the tubes undergoes heat exchange with the air passingbetween the fins with a high degree of efficiency. While it is notpossible to completely eliminate the thermal interference via the finssince the temperature of the fluid flowing inside the tubes of theradiator 9 becomes higher than the temperature of the fluid flowinginside the tubes of the condenser 5, the heat transfer from the radiatorto the condenser can be reduced to a satisfactory degree because of theheat transfer prevention louvers 32 b formed at the fins 4 over theentire area between the tubes 3 of the condenser 5 and the tubes 7 ofthe radiator 9.

As described above, since the heat transfer prevention louvers 32 b areformed continuously to the performance-improving louvers 32 a and theheat transfer prevention louvers 32 b are provided over the entire areabetween the tubes 3 of the condenser 5 and the tubes 7 of the radiator9, a satisfactory heat transfer prevention effect is achieved regardlessof the distance between the tubes 3 of the condenser 5 and the tubes 7of the radiator 9.

FIG. 5 shows the results of a test conducted to prove this point. Basedupon the results presented in the figure, the effect of the heat fromthe radiator 9 can be evaluated in correspondence to the coolant averagepressure at the condenser 5 since there is a correlation between thedegree is of effect of the heat transmitted from the radiator 9 to thecondenser 5 and the coolant average pressure at the condenser 5 in whicheven when the air velocity is constant, the coolant average pressure atthe condenser 5 increases as the effect of the heat transmitted from theradiator 9 to the condenser 5 increases, whereas the coolant averagepressure at the condenser 5 becomes reduced as the effect of the heatfrom the radiator 9 decreases. The results in FIG. 5 were obtainedthrough measurement of the coolant average pressure at the condenser 5performed by continuously supplying warm water at a constant temperature(90° C.) at a constant flow rate (20 L/ min) to the radiator 9 andconcurrently operating the compressor in the air conditioning cycle at aspecific rotating rate (850 rpm) at varying air velocities. In thefigure, the solid line represents measurement results obtained in anintegrated heat exchanger having the fins 4 of the condenser and theradiator constituted as a common member, which is provided only withperformance-improving louvers but with no heat transfer preventionlouvers, and the one-point chain line represents the results achieved inthe integrated heat exchanger described above provided with the heattransfer prevention louvers formed over the entire area between thetubes 3 of the condenser 5 and the tubes 7 of the radiator 9 in additionto the performance-improving louvers.

As the results of the test clearly demonstrate, the integrated heatexchanger 1 adopting the structure described above, which is providedwith the heat transfer prevention louvers 32 b, is capable of reducingthe effect of heat transfer compared to an integrated heat exchangerwithout such heat transfer prevention louvers and this advantage isrealized fully in the low air velocity range in particular. The effectof the heat transfer prevention louvers becomes lessened in the high airvelocity range, since the two heat exchangers achieve full heatexchanging performance at high air flow rates, the effect of heattransfer becomes almost insignificant and, as a result, the effect ofthe heat transfer prevention louvers 32 b becomes less pronounced.

Since the heat transfer prevention louvers 32 b and theperformance-improving louvers 32 a are formed continuously in thestructural example explained above, they can be formed without having todistinguish them from each other according to their functions during themanufacturing process. In particular, since the two louver groups 31 and32 are formed symmetrically to each other in this structure, the designand production processes are facilitated. In addition, since there is norisk of erroneous assembly of fins, an improvement in the productionefficiency is realized. Furthermore, with the louver groups 31 and 32formed symmetrically to each other, good air flow, such as thatindicated by the arrow A in FIG. 4, is achieved.

FIG. 6 shows another example of the relationship that may be assumed bythe louvers 30 at the fins 4 and the individual tubes 3 and 7, and inthis example, the tube width at the radiator 9 is set larger than thewidth of the tubes at the condenser 5. In addition, four louver groups,i.e., first˜fourth louver groups 34˜37, are formed in series along thedirection of the width of the fins 4 (the direction of air flow), withthe individual louvers constituting the first and third louver groups 34and 36 aligned along the same inclining direction, and the individuallouvers constituting the second and fourth louver groups 35 and 37aligned along the direction opposite from the inclining direction of thefirst and third louver groups.

The louver groups are all constituted of equal numbers of louvers 30 andthe individual louver groups 30 are set evenly over uniform intervals.First˜third flat portions 38˜40 are formed in the area between the firstlouver group 34 and the second louver group 35, the area between thesecond louver group 35 and the third louver group 36 and the areabetween the third louver group 36 and the fourth louver group 37, withthe first flat portion 38 formed over an area located between the tubes3 of the condenser 5, the second and third flat portions 39 and 40formed over an area located between the tubes 7 of the radiator 9 andlouvers constituting the second louver group 35 formed at the fins overthe area located between the tubes 3 of the condenser 5 and the tubes 7of the radiator 9.

In other words, the second louver group 35 is constituted bycontinuously forming performance-improving louvers 35 a located betweenthe tubes of the condenser 5, heat transfer prevention louvers 35 blocated between the first louver group and the second louver group andperformance-improving louvers 35 c located between the tubes of theradiator 9 and, in this example, a portion of the second louver group 35is utilized as the heat transfer prevention louvers 35 b with theperformance-improving louvers 35 a and 35 c and the heat transferprevention louvers 35 b inclining along the same direction. In addition,all the louvers 30 in the first, third and fourth louver groups 34, 36and 37 constitute performance-improving louvers 34 a, 36 a and 37 arespectively.

When this structure is adopted, too, since the heat transfer preventionlouvers 35 b are formed over the entire area between the tubes 3 of thecondenser 5 and the tubes 7 of the radiator 9, the heat transfer fromthe radiator to the condenser can be reduced to a satisfactory degree,to achieve an advantage comparable to that indicated in thecharacteristics diagram in FIG. 5. In addition, since the heat transferprevention louvers 35 b are formed continuously to theperformance-improving louvers 35 a and 35 c, it is not necessary todistinguish between them during the manufacturing process and especiallyin this example in which four louver groups are evenly formed, noparticular consideration needs to be taken when forming louvers andthere is no risk of erroneous assembly of the fins. Furthermore, sincethe adjacent louver groups are formed symmetrically to each other, goodair flow, such as that indicated by the arrow B in FIG. 6, is achievedfor the air guided by the louvers.

FIGS. 7 through 10 present other examples of the relationship that maybe assumed by the louvers 30 at the fins 4 and the tubes 3 and 7, and inthese examples, the width of the tubes at the condenser 5 and the widthof the tubes at the radiator 9 are set equal to each other.

The structure shown in FIG. 7 is achieved by forming three louvergroups, i.e. first through third louver groups 41˜43 in series along thedirection of the width of the fin (the direction of the air flow), withthe individual louvers constituting the first and third louver groups 41and 43 aligned along the same inclining direction and the individuallouvers constituting the second louver group 42 aligned along aninclining direction which is opposite from the inclining direction ofthe first and third louver groups 41 and 43.

The individual louver groups are constituted of equal numbers of louversand are set evenly over uniform intervals. First and second flatportions 44 and 45 are formed in the area between the first louver group41 and the second louver group 42 and the area between the second louvergroup 42 and the third louver group 43, with the first flat portion 44formed over an area between the tubes 3 of the condenser 5, the secondflat portion 45 formed over an area located between the tubes 7 of theradiator 9 and louvers constituting the second louver group 42 formed atthe fins 4 located between the tubes 3 of the condenser 5 and the tubes7 of the radiator 9.

In other words, in the second louver group 42, performance-improvinglouvers 42 a and 42 c located between the tubes of the condenser 5 andbetween the tubes of the radiator 9 are formed on two sides, heattransfer prevention louvers 42 b located between the tubes 3 of thecondenser 5 and the tubes 7 of the radiator 9 are formed in the middleand the performance-improving louvers 42 a and 42 c and the heattransfer prevention louvers 42 b are formed continuously. In addition,all the louvers 30 in the first and third louver groups 41 and 43 areconstituted as performance-improving louvers 41 a and 43 a respectively.

When this structure is adopted, too, since the heat transfer preventionlouvers 42 b are formed over the entire area between the tubes 3 of thecondenser 5 and the tubes 7 of the radiator 9, the heat transfer fromthe radiator to the condenser can be reduced to a satisfactory degree,to achieve an advantage comparable to that indicated in thecharacteristics diagram in FIG. 5. In addition, since the heat transferprevention louvers 42 b are formed continuously to theperformance-improving louvers 42 a and 42 c, no particular considerationneeds to be taken when forming louvers and, since the three louvergroups are evenly formed, louver formation is facilitated and there isno risk of erroneous assembly. Furthermore, since the adjacent louvergroups are formed symmetrically to each other, good air flow, such asthat indicated by the arrow C in FIG. 7, is achieved for the air guidedby the louvers 30.

The structure shown in FIG. 8 is achieved by inclining the louversconstituting the third louver group 43 in FIG. 7 in the oppositedirection. While the air does not flow in the serpentine patternindicated by the arrow C in FIG. 7 in this structure in which the thirdlouver group 43′ is not formed to achieve symmetry with the secondlouver group 42, the heat transfer prevention louvers 42 b are formedover the entire area between the tube 3 of the condenser 5 and the tube7 of the radiator 9 to achieve advantages over the prior art in that theheat transfer from the radiator to the condenser is greatly reduced, inthat characteristics that are comparable to those shown in FIG. 5 areachieved and in that the heat transfer prevention louvers 42 b and theperformance improving louvers 42 a and 42 c are formed continuously toeliminate the necessity for distinguishing them from each other duringthe manufacturing process.

The structure in FIG. 9 is achieved by forming two louver groups, afirst louver group 46 and a second louver group 47, in series at eachflat portion along the direction of the width of the fins (the directionof air flow) and forming the second louver group 42 and the third louvergroup 43′ in FIG. 8 continuously to each other to constitute the secondlouver group 47.

Namely, a flat portion 48 is formed between the first louver group 46and the second louver group 47 at a position between the tubes of thecondenser 5, and in the second louver group 47, performance-improvinglouvers 47 a located between the tubes of the condenser 5, heat transferprevention louvers 47 b located between the tube 3 of the condenser 5and the tube 7 of the radiator 9 and performance-improving louvers 47 clocated between the tubes 7 of the radiator 9 are formed continuously.In addition, all the louvers 30 in the first louver group 46 areconstituted as performance-improving louvers 46 a.

As in the structure shown in FIG. 8, the air does not flow in aserpentine pattern in this structure, either. However, it achieves anadvantage in that since no flat portion is present in the area where theair does not readily move in a serpentine pattern, the number ofperformance-improving louvers is increased over this area to improve theheat exchanging performance.

In the structure shown in FIG. 10, first and second louver groups 46′and 47′ formed at a fin are both constituted of parallel louvers 30′lying parallel with the surface of the fin instead of the inclinedlouvers shown in FIG. 9. The parallel louvers 30′ are formed toalternately project out to the front side and the rear side of the fin4, and contribute to an improvement in the heat exchanging performanceover the areas where the performance-improving louvers 46′a, 47′a and47′c are formed by ensuring a smooth airflow effectively blocking heattransfer over the area where heat transfer prevention louvers 47′b areformed.

Other structural features in FIGS. 6˜10 are identical to those adoptedin the structure illustrated in FIGS. 1˜4, and the same referencenumbers are assigned to identical components to preclude the necessityfor repeated explanation thereof In addition, the manner in which thetubes and the louvers should be provided in combination with each otheris not limited to the examples explained above and the structuresexplained above may be combined as appropriate as long as the heattransfer prevention louvers continuous to the performance-improvinglouvers are formed at the fins over the area between the tubes 3 of thecondenser 5 and the tubes 7 of the radiator 9.

INDUSTRIAL APPLICABILITY

As described above, in the parallel integrated heat exchanger havingcommon fins shared by adjacent heat exchangers according to the presentinvention, heat transfer prevention louvers are formed over the entirearea between the tubes of one of the adjacent heat exchangers and thetubes of the other heat exchanger, with these louvers formed continuousto, at least, performance-improving louvers located between the tubes ofone of the heat exchangers and, as a result, the degree to which theadjacent heat exchangers affect each other thermally can be reduced bythe heat transfer prevention louvers.

In particular, since the heat transfer prevention louvers are formedover the entire area between the tubes of one of the adjacent heatexchangers and the tubes of the other heat exchanger, a sufficientdegree of reduction in heat transfer is assured even when the heatexchangers provided in parallel are set over a smaller distance fromeach other. In addition, by forming the heat transfer prevention louverscontinuous to, at least, the performance-improving louvers formed at oneof the heat exchangers and by achieving a uniform formation mode for theindividual louvers continuously formed in this manner, no specialconsideration needs to be taken in the production of the heat transferprevention louvers to facilitate the manufacturing process.

Furthermore, by evenly forming an even number of louver groups achievedby aligning roughly equal numbers of louvers in series along thedirection of the width of the fins when the widths of the tubes of theadjacent heat exchangers are different from each other, or by evenlyforming an odd number of louver groups achieved by aligning roughlyequal numbers of louvers in series along the direction of the width ofthe fins when the widths of the tubes of the adjacent heat exchangersare roughly equal to each other, a louver formation area can be made tocorrespond to the area of the fins located between the tubes of one ofthe adjacent heat exchangers and the tubes of the other heat exchanger.Since this structure requires louver groups with roughly equal numbersof louvers to be formed over uniform intervals at the fins, themanufacturing process is facilitated, and in addition, the heatexchanging performance can be improved by achieving good air flow.

Furthermore, by forming the area between adjacent louver groups formedat the fins as a flat area continuous to the fin surface, a smooth flowof air passing between the fins is assured, whereas by reducing thedistance between adjacent louver groups and forming the area between thelouver groups as a non-flat surface, the ratio of the area occupied bythe louvers at the fin surface can be increased to improve the heatexchanging performance.

What is claimed is:
 1. A parallel integrated heat exchanger having aplurality of heat exchangers, each provided with a heat exchanging unitconstituted with fins and a plurality of tubes laminated via said finsand tanks communicating with said plurality of tubes, with adjacent heatexchangers joined by having said heat exchanging units thereof facingopposite each other and fins of said adjacent heat exchangers formed asan integrated common member, wherein performance-improving louvers areformed between said tubes of said heat exchangers at said fins, and heattransfer prevention louvers are formed continuously along an areaspanning a distance between said tubes of said adjacent heat exchangersat said fins, said heat transfer prevention louvers are formedcontinuous with, at least, said performance-improving louvers of one ofsaid adjacent heat exchangers, wherein said tubes widths at saidadjacent heat exchangers are different from each other, and an evennumber of louver groups are achieved by aligning roughly equal numbersof louvers evenly in series along said fins in a direction in which saidadjacent heat exchangers are provided in parallel at said fins.
 2. Aparallel integrated heat exchanger according to claim 1, wherein auniform formation mode is adopted to continuously form said heattransfer prevention louvers in an identical pattern with saidperformance-improving louvers.
 3. A parallel integrated heat exchangeraccording to claim 1, wherein a flat surface is formed between adjacentlouver groups.
 4. A parallel integrated heat exchanger according toclaim 1, wherein a non-flat surface is formed by reducing the distancebetween adjacent louver groups.
 5. A parallel integrated heat exchangeraccording to claim 1, wherein said louvers are inclined louversinclining relative to the surfaces of said fins at which said louversare formed.
 6. A parallel integrated heat exchanger according to claim3, wherein said louvers are inclined louvers inclining relative to thesurfaces of said fins at which said louvers are formed.
 7. A parallelintegrated heat exchanger according to claim 4, wherein said louvers areinclined louvers inclining relative to the surfaces of said fins atwhich said louvers are formed.
 8. A parallel integrated heat exchangeraccording to claim 2, wherein said louvers are parallel louvers lyingparallel to the surfaces of said fins at which said louvers are formed.9. A parallel integrated heat exchanger according to claim 1, whereinsaid louvers are parallel louvers lying parallel to the surfaces of saidfins at which said louvers are formed.
 10. A parallel integrated heatexchanger according to claim 3, wherein said louvers are parallellouvers lying parallel to the surfaces of said fins at which saidlouvers are formed.
 11. A parallel integrated heat exchanger accordingto claim 4, wherein said louvers are parallel louvers lying parallel tothe surfaces of said fins at which said louvers are formed.
 12. Aparallel integrated heat exchanger according to claim 1, furthercomprising a condenser and a radiator joined as one unit to form saidparallel integrated heat exchanger.
 13. A parallel integrated heatexchanger according to claim 12, wherein said condenser comprises afirst pair of said tanks and said radiator comprises a second pair ofsaid tanks.
 14. A parallel integrated heat exchanger according to claim13, wherein said condenser further comprises a plurality of said tubescommunicating between said first pair of said tanks.
 15. A parallelintegrated heat exchanger according to claim 13, wherein said radiatorfurther comprises a plurality of said tubes communicating between saidsecond pair of said tanks and formed separately from said tubes of saidcondenser.
 16. A parallel integrated heat exchanger having a pluralityof heat exchangers, each provided with a heat exchanging unitconstituted with fins and a plurality of tubes laminated via said finsand tanks communicating with said plurality of tubes, with adjacent heatexchangers joined by having said heat exchanging units thereof facingopposite each other and fins of said adjacent heat exchangers formed asan integrated common member, wherein performance-improving louvers areformed between said tubes of said heat exchangers at said fins, and heattransfer prevention louvers are formed continuously along an areaspanning a distance between said tubes of said adjacent heat exchangersat said fins, said heat transfer prevention louvers are formedcontinuous with, at least, said performance-improving louvers of one ofsaid adjacent heat exchangers, wherein said tubes widths at saidadjacent heat exchangers are roughly equal to each other, and an oddnumber of louver groups are achieved by aligning roughly equal numbersof louvers evenly in series along said fins in a direction in which saidadjacent heat exchangers are provided in parallel at said fins.
 17. Aparallel integrated heat exchanger according to claim 16, wherein a flatsurface is formed between adjacent louver groups.
 18. A parallelintegrated heat exchanger according to claim 16, wherein a non-flatsurface is formed by reducing the distance between adjacent louvergroups.
 19. A parallel integrated heat exchanger according to claim 16,wherein said louvers are inclined louvers inclining relative to thesurfaces of said fins at which said louvers are formed.
 20. A parallelintegrated heat exchanger according to claim 16, wherein said louversare parallel louvers lying parallel to the surfaces of said fins atwhich said louvers are formed.
 21. A parallel integrated heat exchangeraccording to claim 16, further comprising a condenser and a radiatorjoined as one unit to form said parallel integrated heat exchanger. 22.A parallel integrated heat exchanger according to claim 21, wherein saidcondenser comprises a first pair of said tanks and said radiatorcomprises a second pair of said tanks.
 23. A parallel integrated heatexchanger according to claim 22, wherein said condenser furthercomprises a plurality of said tubes communicating between said firstpair of said tanks.
 24. A parallel integrated heat exchanger accordingto claim 22, wherein said radiator further comprises a plurality of saidtubes communicating between said second pair of said tanks and formedseparately from said tubes of said condenser.
 25. A parallel integratedheat exchanger according to claim 16, wherein a uniform formation modeis adopted to continuously form said heat transfer prevention louvers inan identical pattern with said performance-improving louvers.
 26. Aparallel integrated heat exchanger according to claim 16, wherein saidodd number of louver groups are formed along a direction parallel tosaid fins so as to be shared by said heat exchangers.
 27. A parallelintegrated heat exchanger according to claim 17, wherein said louversare parallel louvers lying parallel to the surfaces of said fins atwhich said louvers are formed.
 28. A parallel integrated heat exchangeraccording to claim 18, wherein said louvers are parallel louvers lyingparallel to the surfaces of said fins at which said louvers are formed.